Which tables for cold start?

[brian617]

Brian, thank you for pointing that out. I've been using Dave W's spreadsheet to dial in the VE and it still needs work, but not sure how else to do it other than drive around and keep logging and adjusting the VE tables.....

Its really not that big of deal if your commanded and actual AFRs arent perfect, With a custom build and so many modifiers (tables) in the 427 PCM its tough to pull off. I think I remember cheating my cold AFR table to get the actual I wanted.

[CDeeZ]

Well my comment about the low MAP colums in the VE being weird. I was looking at your bin with the $0E XDF. Opened two instances of TunerPro and loaded your BIN with $0D and my BIN with $0E and the data isn't screwed up now when viewing yours with the wrong XDF. Oops.

Now let's see, where to go from here?

And we still don't know why GM had the Open Loop AFR table stupid rich in that stock 350 4L80 BIN I posted do we????

[CDeeZ]

Well this is revealing doing a side by side here. This has got to be the problem with it not wanting to start when cold and running soo poorly... The factory 350 4L80 bin is commanding a stupid rich AFR for some odd reason???

Check out these screenshots, one is comparing my bin after I leaned it out a bit to sturgills..... And the other one compares the stock 350 4L80 bin to a stock 350 4L60/700r4 bin.... Why in the world did they set up the AFR table so crazy rich in the 350 4L80 bin?????

On an unrelated note, I just snapped in a USB mouse to the tuning laptop, wow what a difference, why didn't I do this a long time ago??? Using the touchpad is such a pain in the ass compared to a real mouse.

[sturgillbd]

My open loop afr table is not stock. I had to enrichen some because I was too lean.. My tune isn't perfect but the last 400 mile round trip I made in my Jeep, I got 19.5 mpg running 60-65 mph on the road and the M38A1 (cj5) is not exactly aerodynamic. I am running the Edelbrock Victor JR 2v Sportsman intake with EQ heads. I have the 1.6875 bore tbi (standard sbc size) and I start going into a vacuum after 4000 rpm. At 6000, my map reading is about 80kpa at WOT. You will have to just play with the values until you get it where you want it. As for a lean pop on cold throttle, the AE settings are easily overshot. I also run 61pph injectors at close to 30 psi. Im a little rich at idle but the pcm compensates decently. You were surprised at the settings difference between the 4L80 bin and mine. Now compare it to some of the CPI bins for the blazers and also look at say a 454 tbi bin like BMHK. Lots of tables that seem fudged just to get GM's desired effect.

[brian617]

the AE settings are easily overshot.

This thread is bringing back a lot of my own early problems LOL.

When running higher pressures on the injectors AE (TPS and MAP) will have to be reduced quite a bit, or did in my case. If the duration of the pulse width during AE is the same high pressure vs low pressure, quite a bit more fuel is being injected at the same PW. Of course this depends on engine combos, intake manifolds etc.

Also -40* Celsius is not likely in Oklahoma

[CDeeZ]

My open loop afr table is not stock. I had to enrichen some because I was too lean.. My tune isn't perfect but the last 400 mile round trip I made in my Jeep, I got 19.5 mpg running 60-65 mph on the road and the M38A1 (cj5) is not exactly aerodynamic. I am running the Edelbrock Victor JR 2v Sportsman intake with EQ heads. I have the 1.6875 bore tbi (standard sbc size) and I start going into a vacuum after 4000 rpm. At 6000, my map reading is about 80kpa at WOT. You will have to just play with the values until you get it where you want it. As for a lean pop on cold throttle, the AE settings are easily overshot. I also run 61pph injectors at close to 30 psi. Im a little rich at idle but the pcm compensates decently. You were surprised at the settings difference between the 4L80 bin and mine. Now compare it to some of the CPI bins for the blazers and also look at say a 454 tbi bin like BMHK. Lots of tables that seem fudged just to get GM's desired effect.

Right, I noticed that you richened it up a little bit. I will try either that table as you set it, or, the even leaner table from the BJYL $0D bin..... Either way, it will be way leaner than the table I've been dealing with from that stock 350 4L80 bin.... My buddy has a CJ2A, a '46... He got it for $25 I think.... Pretty rusty, but still way cool.

Yeah I just don't get why GM set up that 350 4L80 bin (whatever the BCC is) to be so rich in cold temps, or rich everywhere for that matter. But like you said, likely they fudged the tables to get wherever it was they were going.......

This thread is bringing back a lot of my own early problems LOL.

When running higher pressures on the injectors AE (TPS and MAP) will have to be reduced quite a bit, or did in my case. If the duration of the pulse width during AE is the same high pressure vs low pressure, quite a bit more fuel is being injected at the same PW. Of course this depends on engine combos, intake manifolds etc.

Also -40* Celsius is not likely in Oklahoma

Suffering builds character right :) Brian, will you post your tune also when you get a chance please?? You're right, -40*C isn't likely here, but -21*C is possible. A couple years ago we had one night where it got down to -7*F..... I hate the cold.... Give me 100+*F any day thankyou very much lol.

[brian617]

Suffering builds character right :) Brian, will you post your tune also when you get a chance please?? You're right, -40*C isn't likely here, but -21*C is possible. A couple years ago we had one night where it got down to -7*F..... I hate the cold.... Give me 100+*F any day thankyou very much lol.

I'll try to remember to email my .bin to work so I can post it for you. It is based on a BJDR .bin.